Strain wave gearing with input to output braking

ABSTRACT

A braking assembly for a strain wave gearing of a surgical robotic manipulator, the braking assembly including a first braking member fixedly coupled to an input portion of a strain wave gearing of a surgical robotic manipulator; and a second braking member fixedly coupled to an output portion of the strain wave gearing, and wherein during a braking operation the first braking member contacts the second braking member to mechanically brake the input portion to the output portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/520,196, filed Jul. 23, 2019, entitled “STRAIN WAVE GEARING WITHINPUT TO OUTPUT BRAKING,” which is hereby incorporated by reference inits entirety.

BACKGROUND Field

Embodiments related to robotic systems, are disclosed. Moreparticularly, embodiments related to a strain wave gearing with input tooutput braking for a surgical robotic manipulator, are disclosed.

Background

Endoscopic surgery involves looking into a patient's body and performingsurgery inside the body using endoscopes and other surgical tools. Forexample, laparoscopic surgery can use a laparoscope to access and viewan abdominal cavity. Endoscopic surgery can be performed using manualtools and/or a surgical robotic system having robotically-assistedcomponents and tools. For example, a surgical robotic system may includea number of surgical robotic manipulators, including surgical roboticarms, that are mounted to a surgical table and manipulated to performsurgical procedures. It is important, however, for the surgical roboticmanipulators to be precisely manipulated and maintained in a desiredorientation and/or configuration during a surgical robotic procedure.

SUMMARY

A surgical robotic system may include a surgical robotic manipulator,for example a surgical robotic arm, including a number of links whichare connected to one another, and to a fixed structure such as asurgical table, by joints. It is imperative that the various jointsconnecting the links and the robotic arm to the surgical table becapable of fluid motion and lockable in a desired position, particularlyduring a surgical operation. For example, a joint that mounts thesurgical robotic arm to a surgical table may need to pivot the arm froma storage position, to an operating position, in which the arm is lockedduring the surgical procedure.

A rotary or pivot joint may include strain wave gearing (e.g., aHarmonic Drive®) which is made up of a wave generator, a flex spline anda rigid ring or circular spline. The wave generator (and its associatedcomponents) may be considered the input element, while the flex spline(and its associated components) may be considered the output element. Inconventional gearing systems, a holding and/or stopping mechanism(brake) may be connected to the housing and used to restrict the motionof an output shaft or an input shaft relative to the housing. Forexample, the braking mechanism may be attached to a fixed housing withinwhich the gearing system is implemented, and then mechanically(physically) engage the input shaft or the output shaft to brake(secure) the input shaft or the output shaft relative to the housing.One disadvantage of such a braking mechanism, however, is that becausethe brake must essentially brake the entire gearing system to thehousing, it must be relatively large.

The proposed invention, on the other hand, includes a braking mechanismor assembly that mechanically brakes the wave generator (input) to theflex cup or spline (output), and can therefore be much smaller thantraditional braking mechanisms. Representatively, the braking assemblymay include a first braking member and a second braking member. Thefirst baking member may be attached to an input shaft, which is rigidlycoupled to the wave generator. The second braking member may be attachedto the output (free) shaft, which is rigidly coupled to the flex cup.When the brake is engaged, the first member engages with the secondmember, which in turn, mechanically couples the wave generator (input)to the flex cup (output) so that they can no longer move relative to oneanother. Therefore, when the brake is engaged and either a forward or aback driving torque is applied, any motion of the gearbox is blocked.Said another way, the flex cup and wave generator are rigidly coupled toone another when the brake is engaged and the motion is prohibited.Because the braking mechanism is within the strain wave gearing, asopposed to a brake coupled to the housing, the braking mechanism mayhave a smaller envelope size and the overall gearbox may be smaller dueto the torque reduction through the gearbox. Advantages of the assemblydisclosed herein include (1) a reduction in holding torque of thebraking assembly due to the high gear reduction and friction of thestrain wave gearing, (2) a compact design envelope because the brake ispackaged inside an already existing output/input shaft thereby reducingthe overall footprint, and (3) since stopping and/or holding of theinput member to the output member is done directly on the axis ofrotation, the number of components between the output and the brake isreduced.

In one aspect, a braking assembly for a strain wave gearing of asurgical robotic manipulator is provided, the braking assembly mayinclude a first braking member fixedly coupled to an input portion of astrain wave gearing of a surgical robotic manipulator; and a secondbraking member fixedly coupled to an output portion of the strain wavegearing, and wherein during a braking operation the first braking membercontacts the second braking member to mechanically brake the inputportion to the output portion. The first braking member and the secondbraking member may be axially aligned, and during the braking operationa top side of the first braking member contacts a bottom side of thesecond braking member preventing rotation of the input portion relativeto the output portion. In some aspects, the braking assembly includes aspring set brake or a permanent magnet brake. In some cases, the firstbraking member includes a disk that is movable in an axial directionrelative to the second braking member, the second braking memberincludes an electromagnet, and the braking operation occurs in theabsence of power. The input portion may include an input shaft fixedlycoupled to a wave generator that is rotatably coupled to the outputportion, the first braking member may include a disk coupled to theinput shaft, the output portion may include a flex cup that is rotatablycoupled to the input portion, the second braking member is coupled tothe flex cup, and a fixed portion is positioned concentrically outwardto the input portion and the output portion. In some aspects, thesurgical robotic manipulator may include a surgical robotic arm having anumber of links connected by a number of joints, and one of the jointscomprises the strain wave gearing.

In another aspect, a strain wave gearing of a surgical roboticmanipulator is provided and includes an input portion, and outputportion, a fixed portion and a braking assembly. The input portion mayinclude a wave generator fixedly coupled to an input shaft. The outputportion may include a flex cup fixedly coupled to an output shaft andhaving a number of flex cup teeth formed along an exterior surface ofthe flex cup, and the input portion is positioned within the outputportion and rotates to drive a relative movement between the inputportion and the output portion. The fixed portion may include a circularspline with a number of circular spline teeth formed along an interiorsurface of the circular spline, wherein the output portion is positionedwithin the fixed portion and the circular spline teeth engage with theflex cup teeth to rotate the output portion relative to the fixedportion. The braking assembly may include a first braking member coupledto the input portion and a second braking member coupled to the outputportion, and the braking assembly may be operable to prevent a relativemovement between the input portion and the output portion during abraking operation. In some aspects, a movement of the first brakingmember or the second braking member in an axial direction transitionsthe braking assembly between an engaged position in which the firstbraking member contacts the second braking member and a disengagedpositon in which there is a gap between the first braking member and thesecond braking member. In some aspects, the first braking member isoperable to rotate with the input shaft, and movable in an axialdirection. The first braking member may include a top component and abottom component, wherein the top component or the bottom component isoperable to move in the axial direction relative to the other. Thesecond braking member may include an electromagnet coil and a permanentmagnet fixedly coupled to the output portion. The input portion, theoutput portion, the fixed portion and the braking assembly may bealigned along a common axis. The surgical robotic manipulator mayinclude a surgical robotic arm having a number of links connected by anumber of joints, and one of the joints connecting the surgical roboticarm to a fixed structure comprises the strain wave gearing.

In another aspect, the surgical robotic system may include a surgicaltable, a surgical robotic manipulator and a strain wave gearing. Thesurgical robotic manipulator may be coupled to the surgical table, thesurgical robotic manipulator comprising a plurality of links and aplurality of joints that are operable to move with respect to oneanother to move the surgical robotic manipulator. The strain wavegearing may be coupled to at least one of the plurality of joints, thestrain wave gearing comprising a wave generator, a flex cup, a circularspline and a braking assembly operable to prevent a relative movementbetween the wave generator and the flex cup during a braking operation.In some aspects, the surgical robotic manipulator may include a surgicalrobotic arm, at least one joint of the plurality of joints is a pivotjoint connecting the surgical robotic arm to a surgical table, and thestrain wave gearing is coupled to the pivot joint. The braking assemblymay include a first braking member attached to the wave generator and asecond braking member fixedly attached to the flex cup, and wherein thefirst braking member and the second braking member directly engage withone another during the braking operation. In some aspects, during anon-braking operation, the first braking member and the second brakingmember are operable to rotate relative to one another around a commonaxis. The first braking member may include a metal disk and the secondbraking member comprises a permanent magnet. The braking assembly mayinclude a spring set brake. In some aspects, the wave generator, theflex cup, the circular spline and the braking assembly are aligned alonga common axis.

The above summary does not include an exhaustive list of all aspects ofthe present invention. It is contemplated that the invention includesall systems and methods that can be practiced from all suitablecombinations of the various aspects summarized above, as well as thosedisclosed in the Detailed Description below and particularly pointed outin the claims filed with the application. Such combinations haveparticular advantages not specifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention are illustrated by way of example andnot by way of limitation in the figures of the accompanying drawings inwhich like references indicate similar elements. It should be noted thatreferences to “an” or “one” embodiment of the invention in thisdisclosure are not necessarily to the same embodiment, and they mean atleast one. Also, in the interest of conciseness and reducing the totalnumber of figures, a given figure may be used to illustrate the featuresof more than one embodiment of the invention, and not all elements inthe figure may be required for a given embodiment.

FIG. 1 is a pictorial view of an example surgical robotic system in anoperating arena, in accordance with an embodiment.

FIG. 2 is a pictorial view of a surgical robotic arm, in accordance withan embodiment.

FIG. 3 is a simplified pictorial view of strain wave gearing for use ina surgical robotic arm, in accordance with another embodiment.

FIG. 4 is a simplified pictorial view of an input portion of the strainwave gearing of FIG. 3 .

FIG. 5 is a simplified pictorial view of an output portion of the strainwave gearing of FIG. 3 .

FIG. 6 is a simplified pictorial view of a fixed portion of the strainwave gearing of FIG. 3 .

FIG. 7 is a magnified view of a disengaged braking assembly of thestrain wave gearing of FIG. 3 .

FIG. 8 is a magnified view of an engaged braking assembly of the strainwave gearing of FIG. 3 .

FIG. 9 is a block diagram of a computer portion of a surgical roboticsystem, in accordance with an embodiment.

DETAILED DESCRIPTION

In various embodiments, description is made with reference to thefigures. However, certain embodiments may be practiced without one ormore of these specific details, or in combination with other knownmethods and configurations. In the following description, numerousspecific details are set forth, such as specific configurations,dimensions, and processes, in order to provide a thorough understandingof the embodiments. In other instances, well-known processes andmanufacturing techniques have not been described in particular detail inorder to not unnecessarily obscure the description. Reference throughoutthis specification to “one embodiment,” “an embodiment,” or the like,means that a particular feature, structure, configuration, orcharacteristic described is included in at least one embodiment. Thus,the appearance of the phrase “one embodiment,” “an embodiment,” or thelike, in various places throughout this specification are notnecessarily referring to the same embodiment. Furthermore, theparticular features, structures, configurations, or characteristics maybe combined in any suitable manner in one or more embodiments.

In addition, the terminology used herein is for the purpose ofdescribing particular aspects only and is not intended to be limiting ofthe invention. Spatially relative terms, such as “beneath”, “below”,“lower”, “above”, “upper”, and the like may be used herein for ease ofdescription to describe one element's or feature's relationship toanother element(s) or feature(s) as illustrated in the figures. It willbe understood that the spatially relative terms are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures. For example, if thedevice in the figures is turned over, elements described as “below” or“beneath” other elements or features would then be oriented “above” theother elements or features. Thus, the exemplary term “below” canencompass both an orientation of above and below. The device may beotherwise oriented (e.g., rotated 90 degrees or at other orientations)and the spatially relative descriptors used herein interpretedaccordingly.

As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising” specify the presence of stated features, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, steps, operations,elements, components, and/or groups thereof.

The terms “or” and “and/or” as used herein are to be interpreted asinclusive or meaning any one or any combination. Therefore, “A, B or C”or “A, B and/or C” mean “any of the following: A; B; C; A and B; A andC; B and C; A, B and C.” An exception to this definition will occur onlywhen a combination of elements, functions, steps or acts are in some wayinherently mutually exclusive.

Moreover, the use of relative terms throughout the description maydenote a relative position or direction. For example, “distal” mayindicate a first direction away from a reference point, e.g., away froma user. Similarly, “proximal” may indicate a location in a seconddirection opposite to the first direction, e.g., toward the user. Suchterms are provided to establish relative frames of reference, however,and are not intended to limit the use or orientation of any particularsurgical robotic component to a specific configuration described in thevarious embodiments below.

Referring to FIG. 1 , this is a pictorial view of an example surgicalrobotic system 100 in an operating arena. The surgical robotic system100 includes a user console 102, a control tower 103, and one or moresurgical robotic manipulators, for example, surgical robotic arms 104 ata surgical robotic platform 105, e.g., an operating table, a bed, etc.The system 100 can incorporate any number of devices, tools, oraccessories used to perform surgery on a patient 106. For example, thesystem 100 may include one or more surgical tools 107 used to performsurgery. A surgical tool 107 may be an end effector that is attached toa distal end of a surgical arm 104, for executing a surgical procedure.

Each surgical tool 107 may be manipulated manually, robotically, orboth, during the surgery. For example, the surgical tool 107 may be atool used to enter, view, or manipulate an internal anatomy of thepatient 106. In an embodiment, the surgical tool 107 is a grasper thatcan grasp tissue of the patient. The surgical tool 107 may be controlledmanually, by a bedside operator 108; or it may be controlledrobotically, via actuated movement of the surgical robotic arm 104 towhich it is attached. The robotic arms 104 are shown as a table-mountedsystem, but in other configurations the arms 104 may be mounted in acart, ceiling or sidewall, or in another suitable structural support.

Generally, a remote operator 109, such as a surgeon or other operator,may use the user console 102 to remotely manipulate the arms 104 and/orthe attached surgical tools 107, e.g., teleoperation. The user console102 may be located in the same operating room as the rest of the system100, as shown in FIG. 1 . In other environments however, the userconsole 102 may be located in an adjacent or nearby room, or it may beat a remote location, e.g., in a different building, city, or country.The user console 102 may comprise a seat 110, foot-operated controls113, one or more handheld user input devices, UID 114, and at least oneuser display 115 that is configured to display, for example, a view ofthe surgical site inside the patient 106. In the example user console102, the remote operator 109 is sitting in the seat 110 and viewing theuser display 115 while manipulating a foot-operated control 113 and ahandheld UID 114 in order to remotely control the arms 104 and thesurgical tools 107 (that are mounted on the distal ends of the arms104.)

In some variations, the bedside operator 108 may also operate the system100 in an “over the bed” mode, in which the bedside operator 108 (user)is now at a side of the patient 106 and is simultaneously manipulating arobotically-driven tool (end effector as attached to the arm 104), e.g.,with a handheld UID 114 held in one hand, and a manual laparoscopictool. For example, the bedside operator's left hand may be manipulatingthe handheld UID to control a robotic component, while the bedsideoperator's right hand may be manipulating a manual laparoscopic tool.Thus, in these variations, the bedside operator 108 may perform bothrobotic-assisted minimally invasive surgery and manual laparoscopicsurgery on the patient 106.

During an example procedure (surgery), the patient 106 is prepped anddraped in a sterile fashion to achieve anesthesia. Initial access to thesurgical site may be performed manually while the arms of the roboticsystem 100 are in a stowed configuration or withdrawn configuration (tofacilitate access to the surgical site.) Once access is completed,initial positioning or preparation of the robotic system 100 includingits arms 104 may be performed. Next, the surgery proceeds with theremote operator 109 at the user console 102 utilizing the foot-operatedcontrols 113 and the UIDs 114 to manipulate the various end effectorsand perhaps an imaging system, to perform the surgery. Manual assistancemay also be provided at the procedure bed or table, by sterile-gownedbedside personnel, e.g., the bedside operator 108 who may perform taskssuch as retracting tissues, performing manual repositioning, and toolexchange upon one or more of the robotic arms 104. Non-sterile personnelmay also be present to assist the remote operator 109 at the userconsole 102. When the procedure or surgery is completed, the system 100and the user console 102 may be configured or set in a state tofacilitate post-operative procedures such as cleaning or sterilizationand healthcare record entry or printout via the user console 102.

In one embodiment, the remote operator 109 holds and moves the UID 114to provide an input command to move a robot arm actuator 117 in therobotic system 100. The UID 114 may be communicatively coupled to therest of the robotic system 100, e.g., via a console computer system 116.The UID 114 can generate spatial state signals corresponding to movementof the UID 114, e.g. position and orientation of the handheld housing ofthe UID, and the spatial state signals may be input signals to control amotion of the robot arm actuator 117. The robotic system 100 may usecontrol signals derived from the spatial state signals, to controlproportional motion of the actuator 117. In one embodiment, a consoleprocessor of the console computer system 116 receives the spatial statesignals and generates the corresponding control signals. Based on thesecontrol signals, which control how the actuator 117 is energized to movea segment or link of the arm 104, the movement of a correspondingsurgical tool that is attached to the arm may mimic the movement of theUID 114. Similarly, interaction between the remote operator 109 and theUID 114 can generate for example a grip control signal that causes a jawof a grasper of the surgical tool 107 to close and grip the tissue ofpatient 106.

The surgical robotic system 100 may include several UIDs 114, whererespective control signals are generated for each UID that control theactuators and the surgical tool (end effector) of a respective arm 104.For example, the remote operator 109 may move a first UID 114 to controlthe motion of an actuator 117 that is in a left robotic arm, where theactuator responds by moving linkages, gears, etc., in that arm 104.Similarly, movement of a second UID 114 by the remote operator 109controls the motion of another actuator 117, which in turn moves otherlinkages, gears, etc., of the robotic system 100. The robotic system 100may include a right arm 104 that is secured to the bed or table to theright side of the patient, and a left arm 104 that is at the left sideof the patient. An actuator 117 may include one or more motors that arecontrolled so that they drive the rotation of a joint of the arm 104, tofor example change, relative to the patient, an orientation of anendoscope or a grasper of the surgical tool 107 that is attached to thatarm. Motion of several actuators 117 in the same arm 104 can becontrolled by the spatial state signals generated from a particular UID114. The UIDs 114 can also control motion of respective surgical toolgraspers. For example, each UID 114 can generate a respective gripsignal to control motion of an actuator, e.g., a linear actuator, thatopens or closes jaws of the grasper at a distal end of surgical tool 107to grip tissue within patient 106.

In some aspects, the communication between the platform 105 and the userconsole 102 may be through a control tower 103, which may translate usercommands that are received from the user console 102 (and moreparticularly from the console computer system 116) into robotic controlcommands that are transmitted to the arms 104 on the robotic platform105. The control tower 103 may also transmit status and feedback fromthe platform 105 back to the user console 102. The communicationconnections between the robotic platform 105, the user console 102, andthe control tower 103 may be via wired and/or wireless links, using anysuitable ones of a variety of data communication protocols. Any wiredconnections may be optionally built into the floor and/or walls orceiling of the operating room. The robotic system 100 may provide videooutput to one or more displays, including displays within the operatingroom as well as remote displays that are accessible via the Internet orother networks. The video output or feed may also be encrypted to ensureprivacy and all or portions of the video output may be saved to a serveror electronic healthcare record system.

FIG. 2 is a pictorial view of an exemplary surgical robotic manipulatorwhich may include the strain wave gearing with input to output braking,as disclosed herein. Representatively, the robotic manipulator mayinclude a robotic arm 104, a tool drive 220, and a cannula 221 loadedwith a robotic surgical tool 250, in accordance with aspects of thesubject technology. As shown in FIG. 2 , the example surgical roboticarm 104 may include a plurality of links (e.g., links 201-208A-B) and aplurality of actuated joint modules (e.g., joints 211-217) for actuatingthe plurality of links relative to one another. The joint modules mayinclude various types, such as a pitch joint or a roll joint, which maysubstantially constrain the movement of the adjacent links aroundcertain axes relative to others. Also shown in the exemplary design ofFIG. 2 is a tool drive 220 attached to the distal end of the robotic arm104. The tool drive 220 may include a cannula 221 coupled to its end toreceive and guide a surgical instrument 250 (e.g., endoscopes, staplers,etc.). The surgical instrument (or “tool”) 250 may include an endeffector having a robotic wrist 252 and jaws 254 at the distal end ofthe tool. The plurality of the joint modules of the robotic arm 104 canbe actuated to position and orient the tool drive 220, which actuatesthe end effector (e.g., robotic wrist 252 and jaws 254) for roboticsurgeries.

In some variations, the plurality of links and joints of the robotic arm104 can be divided into two segments. The first segment (setup arm)includes links 201-205 and joints 211-215 (also referred to as jointsJ1-J5) that provide at least five degrees of freedom (DOFs). Theproximal end of the first segment can be mounted to a fixture (e.g.,surgical table) at the pivot joint 260 (also referred to as joint J0),while the distal end is coupled to the second segment. The secondsegment (spherical arm) includes links 206-208 providing the arm with atleast two DOFs. Link 208 may comprise a first link 208A and a secondlink 208B operatively coupled with a pulley mechanism to form aparallelogram and to constrain the movement of the tool drive 220 arounda mechanical remote center of motion (RCM). The first segment may bereferred to as the setup arm because it may position and adjust the RCMin space relative to the mounting fixture, while the second segment maybe referred to as the spherical arm because it is configured to move thesurgical tool within the generally spherical workspace. In one aspect,the strain wave gearing with input to output braking as disclosed hereinmay be integrated within the pivot joint 260 (e.g., joint J0) to lock orotherwise brake arm 104 at a desired position once pivoted to/from thestorage position under the table and/or operating position over thetable. In further aspects, the strain wave gearing may be integratedwithin any one or more of the other arm joints disclosed herein (e.g.,joints 211-215).

FIG. 3 illustrates a simplified schematic diagram of one exemplarystrain wave gearing with input to output braking. Representatively,strain wave gearing 300 includes an input portion 302, an output portion304 and a fixed portion 306, which are all arranged around a common axis308 (e.g., rotational axis). The input portion 302 may be rigidlyattached to a motor drive shaft such that rotation of the motor driveshaft may drive a rotation of the input portion 302 around axis 308. Theoutput portion 304 is arranged concentrically outward to the inputportion 302 and may rotate relative to the input portion 302, alsoaround axis 308. The fixed portion 306 may be arranged concentricallyoutward to the input portion 302 and the output portion 304 and may befixed to a housing (e.g., the robotic arm housing) within which thestrain wave gearing is integrated. Both the input portion 302 and theoutput portion 304 may rotate relative to the fixed portion 306 to causea movement of a driven component (e.g., surgical robotic arm).Typically, in gearing systems, as previously discussed, braking of thesystem is accomplished by braking an input or output shaft to thehousing, and therefore requires a relatively large braking mechanism.Braking of strain wave gearing 300, in contrast, is accomplished bymechanically braking (e.g., holding and/or stopping motion) inputportion 302 to output portion 304. In other words, during a brakingoperation, input portion 302 is locked to output portion 304 such thatthey can no longer move relative to one another, which in turn, preventsa net output movement (e.g., to drive the associated driven component).The input portion 302, output portion 304, fixed portion 306 and/orbraking assembly may all be considered to share, be mounted on orotherwise aligned, along axis 308. In some aspects, an axial movement ofone or more of the strain wave gearing components and/or brakingassembly along the axis 308 may be used to brake the input to theoutput. The specific components of the strain wave gearing 300 whichallow for input to output breaking will now be described in reference toFIG. 4 -FIG. 6 .

FIG. 4 illustrates a schematic side view of the input portion 302, FIG.5 illustrates a schematic side view of the output portion 304, and FIG.6 illustrates a schematic side view of the fixed portion 306, previouslydiscussed in reference to FIG. 3 . Referring now to FIG. 4 , inputportion 302 includes a wave generator 402 attached to an input shaft404. The wave generator 402 may be, for example, an elliptical disk,also known as an elliptical plug, which is positioned around shaft 404.In one aspect, input shaft 404 may include a shaft key 406 positionedalong a portion of the shaft within the wave generator 402, and theshaft key 406 attaches the wave generator 402 to the input shaft 404.Although not shown, the input shaft 404 may be fixedly attached to amotor shaft which drives movement of the input shaft 404, and in turn,the wave generator 402. The wave generator 402 may further include anoldham coupler 408 that movably couples the input portion 302 to outputportion 304. Input portion 302 may further include first braking member410 fixedly attached to the other end of the input shaft 404 by shaftkey 412. The first braking member 410 may be a hub which forms the firstpart of the braking mechanism or assembly used to brake the inputportion 302 to the output portion 304. The first braking member 410 may,for example, be a disk shaped member positioned around the end of inputshaft 404, and below the output portion 304, as shown. In some aspects,first braking member 410 may include a top portion 410A and a bottomportion 410B, which are movably coupled to one another by a connectingmember 414. The top plate 410A and/or the bottom plate 410B may move inan axial direction (e.g., a direction parallel to axis 308) toengage/disengage the first braking member 410 with a second brakingmember (e.g., second braking member 510 shown in FIG. 5 ) during abraking operation. For example, the connecting member 414 may be, orinclude, a spring that allows top plate 410A and/or bottom plate 410B tomove in an axial direction relative to one another. Representatively,first braking member 410 may be, or be part of a spring set brake, whichincludes the top and bottom plates 410A, 410B, a spring (e.g. connectingmember 414) biasing the plates away from one another, and anelectromagnet coil. The electromagnet coil could be, for example,incorporated into, or otherwise form a part of, or be coupled to, thesecond braking member 510. During operation, the electromagnet coil canbe powered by a DC voltage which creates a magnetic field strong enoughto override the biasing force created by the spring and pull the plates410A, 410B together, in the axial direction. This, in turn, forms a gapbetween the input portion 302 (including first braking member 410) andthe output portion 304 (including the second braking member 510 shown inFIG. 5 ), and allows them to move relative to one another. To initiate abraking operation (e.g., prevent movement of the output portion 304relative to the input portion 302), the voltage is removed allowing thespring to once again push the plates 410A, 410B away from one another,causing the top plate 410A of the first braking member 410 to contactthe second braking member on the input portion 302, and brake the inputportion 302 to the output portion 304.

As illustrated by FIG. 5 , the output portion 304 may include a flexspline or flex cup 502, which is positioned around the wave generator402 (not shown). The flex cup 502 may be shaped like a cup and have arelatively flexible side wall 504 that is open at one end and coupled toa relatively rigid bottom wall 506 at another end. The flex cup 502 maybe attached to an output shaft 512, which in turn, is attached to thedriven component or is part of the driven component. Flex cup teeth 508may be radially positioned around the outer surface of the side wall504, near the open end. As illustrated in FIG. 6 , the fixed portion 306includes a circular spline (e.g., rigid ring) having an inner surface602 including radially positioned circular spline teeth 604 and theouter surface 606 is fixedly attached to the surrounding housing.

During operation, a rotation of the elliptically shaped wave generator402 within the flex cup 502 causes the flex cup side wall 504 to deform,and in turn, the flex cup teeth 508 to engage with the circular splineteeth 604 of the circular spline and drive a rotation of the flex cup502. For example, as the wave generator 402 rotates in a first direction(e.g., clockwise direction), the flex cup side wall 504 deforms causingthe flex cup teeth 508 to mesh with the circular spline teeth 604. Theflex cup 502 includes fewer teeth than the circular spline such that forevery full rotation of the wave generator 402, the flex cup 502 rotatesa small amount in a second direction (e.g., a counter clockwisedirection), relative to the circular spline. This movement of the flexcup 502, which is part of the output portion 304, in turn, drives adesired movement of the associated driven component (e.g., a surgicalrobotic arm).

If the movement of the flex cup 502 relative to the wave generator 402,however, is prevented, there is no net output movement. In this aspect,the second braking member 510 is attached to the flex cup 502 so thatthe second braking member 510 in combination with the first brakingmember 410 can be used to prevent the relative movement between flex cup502 and wave generator 402. For example, second braking member 510 maybe fixedly attached to, or otherwise near, the bottom wall 506 of flexcup 502, as illustrated by FIG. 5 . In one aspect, the second brakingmember 510 may be a housing which contains, or otherwise includes, theelectromagnet coil and a permanent magnet. The first braking member 410and the second braking member 510 may be axially aligned (e.g., alongaxis 308), or otherwise arranged such that one is above/below the other.Braking may occur when first braking member 410 and/or second brakingmember 510 are moved in an axial direction (e.g., in a directionparallel to the axis 308) toward one another to prevent the relativemovement between wave generator 402 and flex cup 502 (e.g., brake theinput portion 302 to the output portion 304), or away from one another(e.g., to release the braking assembly). In some cases, the brakingassembly or mechanism may be a spring or spring set brake which includesa spring to help driving the braking action. In other aspects, thebraking assembly or mechanism may be a permanent magnet brake. In thecase of a permanent magnet brake, the first braking member 410 mayinclude a metallic surface (e.g., top component 410A) that faces thepermanent magnet (e.g., second braking member 510) and a magnetic forceis used to engage the braking components and brake the input to theoutput.

Representatively, FIG. 7 and FIG. 8 illustrate magnified views of thebraking assembly in both the disengaged and engaged positions. Inparticular, as can be seen from FIG. 7 , when the braking assembly is inthe disengaged position 700, a space or gap 702 is present a top side706 of the first braking member 410 and a bottom side 704 of secondbraking member 510. This gap 702 allows the input portion 302 (e.g.,wave generator 402) to move (e.g., rotate) relative to the outputportion 304 (e.g., flex cup 502), and in turn there is a net outputmovement to a driven member associated with output portion 304. In theengaged position 800 shown in FIG. 8 , the first braking member 410 andthe second braking member 510 are pressed together such that the gap isclosed and their interfacing sides 704, 706 are in contact with oneanother as shown. For example, first braking member 410 may include aspring as previously discussed which drives the movement of firstbraking member 410 axially according to the arrow (e.g., parallel to theaxis of rotation) to transition the braking assembly between thedisengaged and engaged positions. In the engaged position 800, therelative movement (e.g., rotation) between input portion 302 (e.g., wavegenerator 402) and output portion 304 (e.g., flex cup 502) is prevented.This, in turn, prevents a net output movement and brakes the input tothe output so that no further movement can occur. In some aspects, theengaged position 800 occurs in the absence of power, and power must beapplied to transition the assembly to the disengaged position 700. Forexample, in one aspect, a spring may bias at least one of the brakingmembers away from the other braking member in the absence of power. Whenpower is applied, an electromagnetic force is generated that overridesthe biasing force of the spring and causes the at least one brakingmember to move toward the other braking member to the engaged position800. In other embodiments, the permanent magnet may be omitted and anentirely spring controlled braking assembly may be used. In someaspects, the frictional force between the braking members is used toprevent movement of the braking members relative to one another duringthe braking operation. It is further contemplated that in otherembodiments, a magnetic force is generated which prevents movement ofthe braking members relative to one another. Regardless of the brakingforce used, it should be appreciated that because the braking assemblyis integrated into the strain wave gearing, and in turn brakes the inputto the output, as opposed to braking, for example, the output to thehousing, the braking assembly can be relatively small while stillachieving a maximum braking function.

It should be understood that although input portion 302 is describedherein as a wave generator 402 and output portion 304 is described as aflex spline or flex cup 502, the specific strain wave gearing componentsmaking up the input and output portions may be interchanged or reversed.For example, input portion 302 may be a wave generator, a flex spline orcircular spline, and output portion 304 may be the other of a flexspline (or flex cup), a wave generator or a circular spline. Inaddition, in some aspects, the fixed portion 306 may be a circularspline or wave generator. Representatively, contemplated alternativearrangements may include (1) the input portion may be a wave generator,the output portion may be a flex spline (or flex cup) and the fixedportion may be a circular spline; (2) the input portion may be a wavegenerator, the output portion may be a circular spline and the fixedportion may be a flex spline (or flex cup); (3) the input portion may bea flex spline, the output portion may be a circular spline and the fixedportion may be a wave generator; (4) the input portion may be a circularspline, the output portion may be a flex spline (or flex cup) and thefixed portion may be a wave generator; (5) the input portion may be aflex spline (or flex cup), the output portion may be a wave generator,and the fixed portion may be a circular spline; and/or (6) the inputportion may be a circular spline, the output portion may be a wavegenerator and the fixed portion may be flex spline (or flex cup). It iscontemplated that in some aspects when all of the wave generator, theflex spline and the circular spline rotate, combinations (1)-(6) arepossible.

Referring now to FIG. 9 , FIG. 9 is a block diagram of a computerportion of a surgical robotic system, in accordance with an embodiment.The exemplary surgical robotic system 900 may include a user console102, a control tower 103, and a surgical robot 120. The surgical roboticsystem 900 may include other or additional hardware components; thus,the diagram is provided by way of example and not a limitation to thesystem architecture.

The user console 102 may include console computers 911, one or more UIDs912, console actuators 913, displays 914, a UID tracker 915, foot pedals916, and a network interface 918. A user or surgeon sitting at the userconsole 102 can adjust ergonomic settings of the user console 102manually, or the settings can be automatically adjusted according touser profile or preference. The manual and automatic adjustments may beachieved through driving the console actuators 913 based on user inputor stored configurations by the console computers 911. The user mayperform robot-assisted surgeries by controlling the surgical robot 120using one or more master UIDs 912 and foot pedals 916. Positions andorientations of the UIDs 912 are continuously tracked by the UID tracker915, and status changes are recorded by the console computers 911 asuser input and dispatched to the control tower 103 via the networkinterface 918. Real-time surgical video of patient anatomy,instrumentation, and relevant software apps can be presented to the useron the high resolution 3D displays 914 including open or immersivedisplays.

The user console 102 may be communicatively coupled to the control tower103. The user console also provides additional features for improvedergonomics. For example, the user console may be an open architecturesystem including an open display, although an immersive display, in somecases, may be provided. Furthermore, a highly-adjustable seat forsurgeons and master UIDs tracked through electromagnetic or opticaltrackers are included at the user console 102 for improved ergonomics.

The control tower 103 can be a mobile point-of-care cart housingtouchscreen displays, computers that control the surgeon'srobotically-assisted manipulation of instruments, safety systems,graphical user interface (GUI), light source, and video and graphicscomputers. As shown in FIG. 9 , the control tower 103 may includecentral computers 931 including at least a visualization computer, acontrol computer, and an auxiliary computer, various displays 933including a team display and a nurse display, and a network interface938 coupling the control tower 103 to both the user console 102 and thesurgical robot 120. The control tower 103 may offer additional featuresfor user convenience, such as the nurse display touchscreen, soft powerand E-hold buttons, user-facing USB for video and still images, andelectronic caster control interface. The auxiliary computer may also runa real-time Linux, providing logging/monitoring and interacting withcloud-based web services.

The surgical robot 120 may include an articulated operating table 924with a plurality of integrated arms 922 that can be positioned over thetarget patient anatomy. A suite of compatible tools 923 can be attachedto or detached from the distal ends of the arms 922, enabling thesurgeon to perform various surgical procedures. The surgical robot 120may also comprise control interface 925 for manual control of the arms922, table 924, and tools 923. The control interface can include itemssuch as, but not limited to, remote controls, buttons, panels, andtouchscreens. Other accessories such as trocars (sleeves, sealcartridge, and obturators) and drapes may also be needed to performprocedures with the system. In some variations, the plurality of thearms 922 includes four arms mounted on both sides of the operating table924, with two arms on each side. For certain surgical procedures, an armmounted on one side of the table can be positioned on the other side ofthe table by stretching out and crossing over under the table and armsmounted on the other side, resulting in a total of three arms positionedon the same side of the table 924. The surgical tool can also comprisetable computers 921 and a network interface 928, which can place thesurgical robot 120 in communication with the control tower 103.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will be evidentthat various modifications may be made thereto without departing fromthe broader spirit and scope of the invention as set forth in thefollowing claims. The specification and drawings are, accordingly, to beregarded in an illustrative sense rather than a restrictive sense.

1.-20. (canceled)
 21. A surgical robotic system comprising a brakingassembly comprising: a first braking member having a first portion and asecond portion operable to move relative to the first portion; and asecond braking member that is engaged by the second portion during abraking operation to mechanically brake an input portion to an outputportion of a strain wave gear coupled to a surgical robotic manipulator.22. The surgical robotic system of claim 21 wherein the first brakingmember and the second braking member are axially aligned, and during thebraking operation, the second portion of the first braking member movesin an axial direction and contacts the second braking member to preventrotation of the input portion relative to the output portion.
 23. Thesurgical robotic system of claim 21 wherein the braking assemblycomprises a spring set brake or a permanent magnet brake.
 24. Thesurgical robotic system of claim 21 wherein the second portion of thefirst braking member comprises a disk that is movable in an axialdirection relative to the second braking member, the second brakingmember comprises an electromagnet, and the braking operation occurs inan absence of power.
 25. The surgical robotic system of claim 21 whereinthe input portion comprises an input shaft fixedly coupled to a wavegenerator that is rotatably coupled to the output portion, the secondportion comprises a disk coupled to the input shaft, the output portioncomprises a flex cup that is rotatably coupled to the input portion, thesecond braking member is coupled to the flex cup, and a fixed portion ispositioned concentrically outward to the input portion and the outputportion.
 26. The surgical robotic system of claim 21 wherein thesurgical robotic manipulator comprises a surgical robotic arm having anumber of links connected by a number of joints, and one of the jointscomprises the strain wave gear.
 27. A surgical robotic system comprisinga braking assembly comprising: an input portion comprising a wavegenerator fixedly coupled to an input shaft; an output portioncomprising a flex cup fixedly coupled to an output shaft, and the inputportion rotates to drive a relative movement between the input portionand the output portion; a fixed portion comprising a circular splinethat engages with the flex cup to rotate the output portion relative tothe fixed portion; and a braking assembly operable to prevent a relativemovement between the input portion and the output portion during abraking operation.
 28. The surgical robotic system of claim 27 whereinthe braking assembly comprises a first braking member and a secondbraking member, and wherein a movement of the first braking member orthe second braking member in an axial direction transitions the brakingassembly between an engaged position in which the first braking memberengages the second braking member to prevent movement between the inputportion and the output portion and a disengaged position in which thereis a gap between the first braking member and the second braking member.29. The surgical robotic system of claim 27 wherein the first brakingmember is coupled to the input portion and operable to rotate with theinput shaft and move in the axial direction, and the second brakingmember is coupled to the output portion.
 30. The surgical robotic systemof claim 29 wherein the first braking member comprises a top componentand a bottom component, wherein the top component or the bottomcomponent is operable to move in the axial direction relative to theother.
 31. The surgical robotic system of claim 27 wherein the secondbraking member comprises an electromagnet coil and a permanent magnetfixedly coupled to the output portion.
 32. The surgical robotic systemof claim 27 wherein the input portion, the output portion, the fixedportion and the braking assembly are aligned along a common axis. 33.The surgical robotic system of claim 27 wherein the surgical roboticmanipulator comprises a surgical robotic arm having a number of linksconnected by a number of joints, and one of the joints connecting thesurgical robotic arm to a fixed structure comprises the brakingassembly.
 34. A surgical robotic system comprising a braking assemblycomprising: a first surgical robotic component; a second surgicalrobotic component coupled to the first surgical robotic component, thesecond surgical robotic component operable to move relative to the firstsurgical robotic component and comprising a strain wave gear; and abraking assembly operable to brake the movement of the second surgicalrobotic component relative to the first surgical robotic component bypreventing a relative movement between a wave generator and a flex cupof the strain wave gear during a braking operation.
 35. The surgicalrobotic system of claim 34 wherein the second surgical robotic componentcomprises a surgical robotic arm comprising a plurality of links and aplurality of joints, at least one joint of the plurality of joints is apivot joint connecting the surgical robotic arm to the first surgicalrobotic component, and the strain wave gear is coupled to the pivotjoint.
 36. The surgical robotic system of claim 34 wherein the brakingassembly comprises a first braking member and a second braking member,at least one of the first braking member or the second braking member isattached to the flex cup, and wherein the first braking member and thesecond braking member directly engage with one another during thebraking operation.
 37. The surgical robotic system of claim 36 whereinduring a non-braking operation, the first braking member and the secondbraking member are operable to rotate relative to one another around acommon axis.
 38. The surgical robotic system of claim 34 wherein thefirst braking member comprises a metal disk and the second brakingmember comprises a permanent magnet.
 39. The surgical robotic system ofclaim 34 wherein the braking assembly comprises a spring set brake. 40.The surgical robotic system of claim 34 wherein the strain wave gearfurther comprises a circular spline, and the wave generator, the flexicup, the circular spline and the braking assembly are aligned along acommon axis.